very small lightweight pure X11 window manager with tray and menus

 Low resource Window manager ideal for older PCs. It uses a minimum of external
 libraries, thus very little memory, includes virtual screens, menubar and
 root-menu popup.
 .
 JWM is a window manager for the X11 Window System. JWM is written in
 C and uses only Xlib and (optionally) the shape extension and libXpm.
 It can support some MWM, GNOME, and WM Spec hints. The menu
 configuration files are managed in XML format.
 .
 Compared to other light WM, like Fvwm95, the Jwm consumes considerably
 less memory while providing the same functionality.